Potted electrical subassembly



March 25, 1952 K|sER 2,590,821

POTTED ELECTRICAL SUBASSEMBLY Filed Nov. 4, 1948 INVEN TOR.

JAMES LEROY KISER ATTORNEY Patented Mar. 25, 1952 POTTED ELECTRICAL SUBASSEMBLY James L. Kiser, Alexandria, Va., assignor to Melpar, Inc., Alexandria, Va.

Application November 4, 1948, Serial No. 58,179

Claims. 1

This invention relates generally to devices for facilitating electrical wiring, and more particularly to systems for readily enablin the compact inter-connection of a plurality of radio components in a small volume.

It is a :broad object of the present invention to provide a system for facilitating electrical inter-connection of electrical or radio components intended to occupy a small volume.

7 It is a further broad object of the present invention to provide a novel terminal board for electrical wiring.

Briefly described, my invention comprises a structure fabricated of plastic and containing, embedded therein, a plurality of metallic rods. In one preferred embodiment of the invention the member may be fabricated in the form of a pair of plane sheets occupying mutually perpendicular planes, the metallic rods extending parallel to the line of intersection of the planes. This specific shape may be adopted for purposes of convenience, but does not partake of the essence of the invention, in accordance with which arcuate sheets may be employed, or single plane sheets, or structures of any other desired form or shape which may be convenient for performing a given wiring operation.

The electrical elements which are to be interconnected are secured to the terminal board 'by being wired to the metallic rods, access to which is provided as required by drilling a small hole through the plastic material to the rod. The ends of the rods may be left uncovered, in forming the plastic about the rods, to provide some terminals accessible without drilling. Each rod, moreover, may be drilled entirely therethrough, to form a pair of electrically isolated collinear rods, if required.

One end of each of the rods may protrude from the plastic material sufficiently to enable forming of the ends to a contour adapted to enable the ends to be inserted in the apertures of a multicontact plug-in socket, the assembled and prewired electrical or radio components providing thus a pre-wired plug-in sub-assembly.

When an entire sub-assembly has been completely wired the terminal board with its assembled components may be potted or cast in plastic material, preferably of the same character as that comprising the terminal board, to protect the wired elements against shock or changes in atmospheric conditions.

The above and still further objects, features and advantages of the present invention will become evident upon consideration of the following detailed description of one specific embodiment thereof, especially when taken in conjunction with the accompanying drawings, wherein:

Figure 1 is a view in perspective illustrating a a complete sub-assembly fabricated in accordance with the invention; and,

Figure 2 is a fragmentary view illustrating a conductive rod embedded in a plastic sheet havingan aperture for permitting access to the rod.

Referring now more specifically to the drawings, and particularly to Figure 1 thereof, the reference numeral I identifies a plastic sheet formed of two plane structures 2 and 3 integrally secured together at right angles to one another. Passing through eachof the plane structures, and embedded completely therein, are electrically conductive rods numbered 4 to [3, inclusive, ends M of each of which protrude slightly from one edge l5 of the plane structures 2 and 3, and the otherends l6 of which protrude extendedly from the opposite edges ll. The ends is are then formed, as by means of a suitable die, to a contour adapted to enable the ends 5 to be inserted in the apertures of a multi-contact plug-in socket (not illustrated) The various electrical elements, such as a mini-1 ature electronic valve I8, a transformer l9, and:

resistors 20, 2|, 22 may be electrically connected to the conductive rods 4-I3, in a manner determined by the desired inter-connections thereof, by means of leads 23, which may be soldered selectively to the conductive rods via apertures 24 formed by removing the material of the plastic sheet I sufiiciently to expose a small portion of I the rod as desired, or which may be extended to the otherwise exposed end portions 14 of the rods. Operating potentials may be supplied to the electrical components, as to the electronic valve l8 or to the transformer l9, via certain ones of the rod ends l6, and output signals taken from others of the rod ends l6, as desired, and in accordance with any predetermined wiring plan.

The plastic sheets 2, 3, provide then a rigid support for the electrical elements to be interconnected, and the rods 4I3, inclusive, provide, in effect, rigid bus bars to which connection may be made at any convenient place, the rods being, however, normally insulated. The rods themselve then provide plug-in terminals. a

It will be noted that resistor 22 is located exteriorly of the angle formed by the sheets 2 and 3. Any number of electrical elements may be so located, if desired, since the rods 4-l3, inclusive, are equally accessible from either side of the sheets 2, 3.

The device of the invention, accordingly pro vides an extremely efficient device for faci1itating wiring of electrical components into a unitary sub-assembly. In practice, and by means of numerous production tests, it has been estab-- lished that a sub-assembly may be completely Wired by utilizing the device of the invention,

were tested. The assembly, when completed, is rigid and provides solid support for the electrical elementsinterconnected, so that they'may be handle without being damagedby slight lack of care and hence without the exercise of extreme and time consuming caution.

After a sub-assembly has beencompleted it may be potted, or cast, in plastic material 25, which may be of the same character as the-material of which the structure 1 is formed,- the latter then being substantially.invisiblewwithin the casting, even if the latter is translucent. The completed casting is substantially impervious to shock, or to variations of atmospheric conditionsfbesides being extremely compact,.and thus lends'itself Well to miniaturization in the field of radioconstruction.

Reference is .heremade to. prior. application forUfS; Patent, Serial #43437, filed in the name of Russell E. Cunningham on August 10, 1948, and entitled Potting of Electrical- Components, which disclosed novelinethods and expedients relating to-theart of potting and casting electricalcomponents .within plastic material, Without damage to the components Or cracking of the plastic. These methods and expedients may be employed incasting of sub-assemblies Wired. in accordance. with the present invention.

"-Whi-le Ihave described one specific example of my'invention, 'in:accordance with the requirements cit-the statues-oilthe United States-relating to Letters-Patent, it willbe clear: that Variations of the specific structure and arrangement described and illustrated may :be ,resorted .to without departing-from the true spirit and. scope or the invention.

Wha-t I claim' and desire to secure by Letters Patent of "theUnited'States is:

1. -A wired structure comprising a unitary sheet of plastic material, said sheet having a longitudinal bend to provide elements in planes at an angle to one-anotherpsaidsheetxcomprising a plurality-of metallic rods each comprising an extended portion completely embedded in said sheet and extending parallel to said longitudinal bend, and-a further portion extending from said sheet, a-"plural-ityof electronic components having leads, aplurality'of apertures extending through said plastic material to selected ones of said rods, soldered-connections from said leads to said rods via said apertures, and a mass of plastic material enclosing said sheet of plastic material and saidelectronic components and said soldered connections, and free of said further portionsof said-rods extending from said sheets.

A structure for facilitating wiringof a subassembly suitable for plug-in to a socket, comprising, 'asheet of plastic material having a longitudinal dimension, a plurality of" metallic rods "extending through said plastic material parallel to one another in said longitudinal dimension,-an-extended portion-of each of said rods completely embedded in said plastic materiaLandan end portion of each of said rods extending from said plastic'material, said end portions-bent to provide prongs for insertion intosaid'socket, a plurality of electronic components having leads, -a plurality of apertures extending through said plastic material to selected' ones of said rods, connections from said leads to said rods via said apertures, and a mass of plastic material enclosing said sheet of plastic material and saidelectronic .components and said connections, andfree of saidend portions of said rods extending from said sheet of plastic ma terial.

.3. A-pottedz,assemblyvof e-lectrical,components adapted for-plug in to asocketihavingaplurality of apertures, comprising, a sheet of plastic -material, having a longitudinal dimension and electrically conductive rods-a pluralityof electrical components of -diverse nature, means for connecting said electrical. components to'said rods viasaid-apertures in saidplastic sheet, and amass of nonhygroscopic andrelatively shockproof plastic-"potting -material enclosing said sheet of plastic material, andsaid electrical components, to provide a potted assembly of wired electrical components having. prongs for insertion into said socket.

4. A structureiorv facilitatingwiring of. a subassem-bly suitable, for plug-in to a multi-prong socket, comprising, a sheet of plastic material having a longitudinal dimension, a plurality of metallic rods having; portions, embedded .in 1 saidsheet: of plastic material. and extending parallel to. one another-and, para1lel..to ..said .longitudL naldirection,..said.- metallic.- rods each.- having an end portionextending; from-saidsheetof, plastic material, said end-portions bent to provide multiple prongsfor said. multi -prong socket, at least one.electrical component havingatleast one lead, an .aperturein said sheet of plastic materialextending atleast to one of said metallic rods, means for connecting said at leastone lead via said aperture to, said one of said metallic rods, and a massof plastic material surrounding said sheet of plastic material and said at least one electrical component andiree of said end portions.

5. A wiredstructure, comprising, a relatively thin sheet of plastic material, azmetallic rod extending longitudinally through said sheet of plastic material and embedded therein, an end of.-sa-id=' rod extendingroutside-said sheet of. plastic material, an opening in said sheetrof plastic material exposing said metallic rod,an electrical component connected to said rod via said opening, a mass of plastic material enclosing said sheet-oiplastic. materialand: said, electrical component andexposing said end of said, rod.

, JAMES .L...KISE,R.

. REFERENCES CITED.

The following :references are r of record in the file of'this patent:

UNITED STATES PATENTS Number Name Date 1,481,278' Wood .Jan.22, 1924 1,718,993 Wermine July- 2,1929 1,719,284 Barnes July 2,1929 2,019,625 O'Brien Nov. 5, 1935 2,175,145 Davison Oct. 3, 1939 FOREIGN PATENTS- Number Country Date 470,252 France Sept. 3, 1914 

